Improvement in musical transposing-indexes



I. L. DEER. Musicai Transposing Indexes.

Patented Dec: 17, 1872 NITED STATES PATENT OrFIcE.

lMPROVEMENT IN MUSICAL TRANSPOSlNG-INDEXES.

Specification forming part of Letters Patent No. 134,001, dated December 17, 1872.

To all whom it may concern;

Be it known that I, JosnPH L. OBER, of Beverly Farms, in the county of Essex and State of Massachusetts, have invented an Improved Musical Transposing-Index, of which the following is a specification:

Figure l is a face view of my improved musical transposing-indcx. Fig; 2 is a back view of the foldin g-stri p containing the flats. Fig. 3 is a transverse section of the index.

The invention consists in combining with a sliding index-plate and natural scale a sharp scale and a flat scale on separate plates that are hinged together and notated so that the two scales can never appear simultaneously to the eye of the learner.

In the drawing, the letter H represents a sliding index-plate, of suitable size, arranged on a bed-plate, I, which is or maybe grooved to receive it. On the face of the index-plate are marked lines it h, which are 1 to 8, as shown, and also marked Do, Re, Mi, Fa, Sol, La, Si, Do, to represent the notes of an octave. These lines -h h are so spaced that the distance between Mi and Fa and between Si and D0 will only be half the distance between all other lines, as there are only semitones from Mi to Fa and from Si to Do in every octave of the major scale, while the others are full tones. On one side of the slide H are marked upon the plate 1 lines 6 2', O D E F G A B O, 860., the spaces between E and F and between 15 and 0 being half the lengths of the other spaces and equal to the spaces between the lines 3 and A and 7 and 8 of the slidingindex. A representation of the keys of a pianoforte is arranged near the lines t', and corresponding thereto in such a manner that every line t will be opposite a white key, Z, of the key-board whosename correspondswiththename marked to the line a". The black keys m m of the same key-board correspond in position with lines a a marked on the opposite side of the index, as shown in Fig. 1, and denominated C sharp, D sharp, F sharp, G sharp, A sharp, C sharp, Ste. On this sharp scale the spaces between D sharp and F sharp and between A sharp and C sharp are one and ahalf times aslarge as those between the other sharps. A folding plate, J, marked on the reverse with the same lines a, whose names, however, are changed to their respective flats, as shown in Fig. 2, is hinged to the side of the plate I, to be folded over the scale of sharps if the plates only are to be read.

The operation is easy to comprehend. If the index is moved to bring the line It (marked 1 or Do) opposite the line 'i (marked 0) the key of 0 natural will be shown, all the lines It being in line with lines i, and none with lines a. When Do is moved opposite to F, as in Fig. 1, the key of F, containing B flat, will be shown.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The combination, with sliding plate and fixed sharp scale, notated as described, of a flat scale, J, hinged to said sharp scale and folding thereover, at the time, in the manner, and for the purpose specified.

JOSEPH LOW OBER.

YVitnesses:

JOHN R. OBER, ALVIN WILLIAMs, D. WooDnERRv. 

